1. Field of the Invention
The present invention pertains generally to adapters for mogul base open fixture lamps.
2. Description of the Related Art
Metal halide lamps include a relatively centrally located arc tube situated within the confines of an outer glass bulb. These arc tubes are conventionally made of quartz and operate at extremely high temperatures and relatively high pressures. Under certain undesirable conditions, a system failure or internal factors will result in a safety hazard being created, whereby a violent shattering of the arc tube will send hot glass and lamp parts into contact with the bulb glass which, in turn, will break, releasing the hot glass and lamp parts into the surrounding environment. Under such conditions, there is an obvious risk of severe personal injury, fire and/or property damage.
For this reason, normally such conventional metal halide unshrouded lamps are supported within what are referred to as “enclosed” fixtures whose structure is designed to contain violently released hot glass and lamps parts. A cover lens is used in such fixtures. In addition, significant reductions in such potential violent failures can be achieved by replacing the lamp before the rated end of the life of the lamp. Another conventional manner in which such potential violent failures are reduced includes the user's periodically turning off the lamp to permit its cooling, so that upon relighting, a non-violent or less violent lamp failure is facilitated.
Recent developments in the field of low wattage metal halide lamp technology affects both lamps and lampholders. Manufacturers of metal halide lamps are selling lamps for use in what are referred to as “open” fixture, in which the lamp is mounted such that it is exposed during its use. In order to reduce or eliminate the risks associated with violent lamp failures in non-enclosed environments, a newer metal halide shrouded lamp has been developed in which a relatively thick shroud of quartz is situated intermediate the arc tube and the outer bulb glass such that, it the event of a violent lamp failure of the type described above, the shroud is intended to intercept and contain the hot glass and lamp parts which would otherwise impact and possibly break the bulb glass. The intended result is a less expensive and equally safe lamp and fixture combination suitable for indoor commercial lighting applications such as offices and retail spaces, as well as other environments.
To prevent the use of conventional unshrouded lamps intended to be used in an “enclosed” fixture in an “open” fixture, the newer shrouded lamp is provided with a different type of base so that the shrouded lamps intended for an open” fixture can be rapidly identified and separated from unshrouded lamps that must be used in an “enclosed” fixture.
There is a need for a device that allows the use of new shrouded lamps with existing “enclosed” fixtures.